NCERT Miscellaneous Exercise Q10 - Probability
Question: Bag I contains 3 red and 4 black balls; Bag II contains 4 red and 5 black balls. One ball is transferred from Bag I to Bag II and then a ball drawn from Bag II is red. Find the probability that the transferred ball was black.
Answer: 16/31.
Full step-by-step NCERT solution with diagrams on Something by Zero.